1. Field of the Invention
The present invention relates to a spindle motor and a recoding disk driving device including the same.
2. Description of the Related Art
A hard disk drive (HDD), an information storage device, reads data stored on a disk or writes data to a disk using a read/write head.
A hard disk drive requires a disk driving device capable of driving the disk. In the disk driving device, a small-sized spindle motor is used.
Meanwhile, the spindle motor according to the related art requires floatation force for rotating a rotor. In this case, in order to prevent the rotor from being separated from a stator when an amount of force equal to or greater than the floatation force required for rotating the rotor is generated in the spindle motor or an external impact is applied to the spindle motor, a pulling plate has been disposed below a driving magnet to suppress the floatation force.
Alternatively, a configuration in which the pulling plate is omitted and the driving magnet is installed in a rotor hub so that the magnetic center of the driving magnet is disposed at a position higher than that of the magnetic center of a stator core in an axial direction to generate force downwardly in an axial direction, thereby preventing the rotor from being separated from the stator when an amount of force equal to or larger than the floatation force is generated in the spindle motor or the external impact is applied to the spindle motor has been adopted.
However, in the case in which the magnetic centers of the driving magnet and the stator core, that is, the centers of the driving magnet and the stator core are not disposed to coincide with each other in the axial direction, noise and vibrations may occur. Further, in the case in which the driving magnet is installed within the rotor hub, it may be relatively difficult to install the driving magnet at a predetermined position. As a result, manufacturing yield may be deteriorated.
Meanwhile, the rotor hub has a disk mounted thereon. To this end, the rotor hub is provided with a clamp member. In addition, the clamp member may be inserted into a clamp hole of the rotor hub to thereby be fixedly installed therein.
However, at the time of installing the clamp member, foreign objects may be introduced into an internal space of the rotor hub through the clamp hole.